Chuwa Maru was a cargo ship. The characters are 中和丸. Osaka Iron Works laid her down at Sakurajima on 13 June 1939 for Nitto Kogyo Kisen of Tokyo, launched her on 30 November, and completed her on 18 March 1940. She was registered at Tokyo, at 2,719 gross tons.
The navy requisitioned her on 5 September 1941 and registered her on 20 September as an auxiliary transport, in the Sasebo Naval District. The conversion was finished at Mako, in the Pescadores, on 1 October. Through the winter she ran between Sasebo, Takao, Mako, and Keelung.
On 10 February 1942 she left Keelung for Naha. Trout was east of the port, bound home from Corregidor. Frank W. Fenno had the submarine. At 1630 a torpedo from about 2,000 yards missed. At 1700 two more hit. About twenty-five minutes later the sound gear heard four explosions, her boilers going. She had been abandoned. She sank at 25°30′N, 122°38′E. No men are recorded lost with her.
She was taken off the navy list on 1 April 1942.